1

I've got an array of data containing stdClass Objects that looks like this if I do print_r($results):

Array ( 
    [0] => stdClass Object ( 
        [ID] => 1 
    ) 
    [1] => stdClass Object ( 
        [ID] => 2 
    ) 
    [2] => stdClass Object ( 
        [ID] => 3 
    ) 
)

I need to get the values of ID as a comma seperated string. To do this, I intially tried to do implode(",", $results) but this gave errors due to the stdClass Objects. So after a reasonable amount of reading and checking SO etc, I've got to a point where I can access the value of ID on a given record: $results[0]->ID.

However, I don't know how many rows there will be due to this data coming from a DB query. So, I need to iterate through each row and add this to a string.

I -amongst other things- tried this:

$i = 0;
foreach ($results as $result){

    //$result->ID;
    $result[$i]['ID'];
    $i++

}

These return an error:

Fatal error: Uncaught Error: Cannot use object of type stdClass as array

I've literally no idea at this point how to get all the ID values as a comma seperated string.

I've checked out numerous SO posts include the following: - 'Cannot use object of type stdClass as array' using Wordpress - iterating through a stdClass object in PHP - PHP Loop stdClass Object

UPDATE I'm getting this data as follows:

global $wpdb;    
$query = "Select wp_users.ID from wp_users where wp_users.ID not in ( select wp_usermeta.user_id from wp_usermeta where wp_usermeta.meta_key = 'grp2_profile_visiblity' and wp_usermeta.meta_value = 1 order by wp_usermeta.user_id ) order by wp_users.ID"; 
$results = $wpdb->get_results( $query, OBJECT );

Thanks

Improve this question
6
  • How do get the data from the DB query - you may be able to do this there rather than mangle the output. Commented Dec 21, 2018 at 17:07
  • Your provided code would return more than that error, since you've got an undefined constant i being used which I'm guessing you meant to be $i which doesn't make sense given the data you've shown. You may want to read up on how foreach works, the idea is to get rid of the iteration counter used in old fashioned for loops. Commented Dec 21, 2018 at 17:46
  • @miken32 - Yeah that is messed up. I was frustrated and trying to type quickly whilst entertaining kids. Commented Dec 21, 2018 at 17:58
  • No worries, give my answer a try and let me know how it works for you (once you get the kids to bed!) Commented Dec 21, 2018 at 18:04
  • @miken32 Ive added the queury to my question. Commented Dec 21, 2018 at 18:05

2 Answers 2

Reset to default
2

You're getting-

Fatal error: Uncaught Error: Cannot use object of type stdClass as array

Fatal error because PHP array's are accessible using bracket [] notation and object's are arrow ->

Let's do this way using foreach() and implode() to get comma separated id's like 1,2,3 but I also think you can fix it from your DB query end without mangling output here :) hope this helps sir.

$expected = [];
foreach ($results as $key=>$obj){
    $expected[] = $obj->ID;
}
echo implode(',',$expected);

WORKING DEMO: https://3v4l.org/oUCkL

Improve this answer
Sign up to request clarification or add additional context in comments.

1 Comment

Ive added the SQL query as an edit to my OP. If you can suggest a way to get the desired results, via SQL I'd love to learn it. Thanks.
1

This is easily enough done with array_column() to get the ID values; it works just as well with objects as it does with arrays.

<?php
// some sample data
$results = json_decode('[{"ID": 1}, {"ID": 2}, {"ID": 3}]');

$return = implode(",", array_column($results, "ID"));
echo $return;

Output:

1,2,3
Improve this answer

7 Comments

That’s surprising but as long as you got something that works. PHP’s functions for handling arrays are generally faster than loops. They’re certainly prettier ;)
Ive added the SQL query as an edit to my OP. If you can suggest a way to get the desired results, via SQL I'd love to learn it. Thanks.
I think you’d be looking for GROUP_CONCAT but I’ve never used it myself.
Yeah, your solution was my preffered option until I checked the performance tab of Curious_Mind's demo. I then tried your's and it came out slower and slightly more memory. 3v4l.org/oUCkL
I would take those numbers with a grain of salt; 15 MB of memory for a 3 element array suggests that is almost entirely PHP overhead, and there's huge variability showing in the execution times between different minor versions. Larger arrays will give clearer ideas of performance, e.g. this versus this, but even that is pretty inconclusive.
|

Start asking to get answers

Find the answer to your question by asking.

Ask question

Explore related questions

See similar questions with these tags.